Lift device with user contact sensor

ABSTRACT

A lift device includes a chassis, a platform configured to support a user, a lift assembly coupling the platform to the chassis, an actuator configured to at least one of (a) move the platform relative to the chassis or (b) propel the chassis, a sensor assembly, and a controller. The sensor assembly includes a bar including a first end portion coupled to the platform and a second end portion opposite the first end portion and a housing defining an aperture sized to receive the second end portion of the bar. The sensor provides a signal in response to at least one of (a) the second end portion of the bar contacting the sensor or (b) the second end portion of the bar exiting the aperture. The controller is operatively coupled to the sensor and the actuator and configured to control the actuator based on the signal from the sensor.

CROSS-REFERENCE TO RELATED PATENT APPLICATIONS

This application is a continuation of U.S. application Ser. No.17/580,342, filed on Jan. 20, 2022, which claims the benefit of andpriority to U.S. Provisional Application No. 63/140,037, filed on Jan.21, 2021, the entire disclosures of which are hereby incorporated byreference herein.

BACKGROUND

The present disclosure relates generally to the field of lift devices.More specifically, the present disclosure relates to sensor systems forlift devices.

Some lift devices include platforms that support a user. Such platformsare often supported by boom assemblies that facilitate vertical and/orhorizontal movement of the platform as controlled by the user through auser interface. During operation, the user is typically positioned infront of the user interface when the platform is moving. As the boomassembly moves the platform, the platform may approach an obstacle(e.g., a wall, a tree branch, etc.). If the user is positioned betweenthe user interface and the obstacle while the platform moves, the user'sfreedom of movement may be restricted.

SUMMARY

At least one embodiment relates to a lift device including a chassis, aplatform configured to support a user, a lift assembly coupling theplatform to the chassis, an actuator configured to at least one of (a)move the platform relative to the chassis or (b) propel the chassis, asensor assembly, and a controller. The sensor assembly includes a barincluding a first end portion coupled to the platform and a second endportion opposite the first end portion and a housing defining anaperture sized to receive the second end portion of the bar. The sensorprovides a signal in response to at least one of (a) the second endportion of the bar contacting the sensor or (b) the second end portionof the bar exiting the aperture. The controller is operatively coupledto the sensor and the actuator and configured to control the actuatorbased on the signal from the sensor.

Another embodiment relates to a sensor assembly for a lift device. Thesensor assembly includes a rod including a first end portion, a secondend portion opposite the first end portion, and a resilient memberextending between the first end portion and the second end portion. Thesensor assembly further includes a hinge coupled to the first endportion of the rod and configured to pivotally couple the rod to aplatform of the lift device. The sensor assembly further includes ahousing configured to be coupled to the platform, the housing definingan aperture sized to receive the second end portion of the rod. Thesensor assembly further includes a sensor configured coupled to thehousing and configured to provide a signal in response to least one of(a) the second end portion of the rod contacting the sensor or (b) thesecond end portion of the rod exiting the aperture. The resilient memberis configured to apply a biasing force to resist movement of the secondend portion away from the sensor.

Another embodiment relates to a lift device including a chassis, aplatform configured to support a user, the platform including a firstrail and a second rail, a user interface coupled to the platform andpositioned between the first rail and the second rail, a lift assemblycoupling the platform to the chassis, an actuator configured to at leastone of (a) move the platform relative to the chassis or (b) propel thechassis, a sensor assembly, and a controller. The sensor assemblyincludes a rod including (a) a first end portion coupled to the firstrail, (b) a second end portion opposite the first end portion, and (c) aresilient member extending between the first end portion and the secondend portion. The sensor assembly further includes a plate coupled to thesecond rail and defining an aperture sized to receive the second endportion of the rod. The sensor assembly further includes a sensorpositioned to detect the second end portion of the rod when the secondend portion of the rod is received by the aperture. The controller isoperatively coupled to the sensor and the actuator and configured tocontrol the actuator in response to an indication from the sensor thatthe second end portion of the rod has exited the aperture.

This summary is illustrative only and is not intended to be in any waylimiting. Other aspects, inventive features, and advantages of thedevices or processes described herein will become apparent in thedetailed description set forth herein, taken in conjunction with theaccompanying figures, wherein like reference numerals refer to likeelements.

BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a front perspective view of a boom lift, according to anexemplary embodiment;

FIG. 2 is a top perspective view of a base assembly of the boom lift ofFIG. 1 , with a turntable removed;

FIG. 3 is a top perspective view of a portion of the base assembly ofFIG. 2 ;

FIG. 4 is a front perspective view of a platform of the boom lift ofFIG. 1 ;

FIG. 5 is a block diagram of a control system of the boom lift of FIG. 1;

FIG. 6 is rear perspective view of a user interface and a railing of theplatform of FIG. 4 with the user interface in a maintenance position;

FIG. 7 is a front, top perspective view of the user interface and therailing of FIG. 6 with the user interface in the maintenance position;

FIG. 8 is a top perspective view of a user contact sensor coupled to theplatform of FIG. 4 ;

FIG. 9 is a left perspective view of the user contact sensor of FIG. 8and the platform of FIG. 4 ;

FIG. 10 is a top section view of the user contact sensor of FIG. 8 ;

FIGS. 11 and 12 are exploded views of the user contact sensor of FIG. 8;

FIGS. 13 and 14 are section views of the user contact sensor of FIG. 8 ;

FIGS. 15, 16, and 17 are various views of a bar assembly of the usercontact sensor of FIG. 8 ;

FIGS. 18, 19, 20, and 21 are rear perspective views illustrating a firstoperating sequence of the platform of FIG. 4 and the user contact sensorof FIG. 8 ;

FIGS. 22, 23, and 24 are rear perspective views illustrating a secondoperating sequence of the platform of FIG. 4 and the user contact sensorof FIG. 8 ;

FIG. 25 is a perspective view of a platform and a user contact sensoraccording to another embodiment;

FIG. 26 is a front section view of the platform and the user contactsensor of FIG. 25 ;

FIGS. 27 and 28 are perspective views of the platform and the usercontact sensor of FIG. 25 ;

FIG. 29 is a section view of the user contact sensor of FIG. 25 ; and

FIG. 30 is a schematic diagram of a switch assembly of the user contactsensor of FIG. 25 .

DETAILED DESCRIPTION

Before turning to the figures, which illustrate certain exemplaryembodiments in detail, it should be understood that the presentdisclosure is not limited to the details or methodology set forth in thedescription or illustrated in the figures. It should also be understoodthat the terminology used herein is for the purpose of description onlyand should not be regarded as limiting.

Referring generally to the figures, a lift device includes a platformconfigured to support a user, a chassis, and a lift assembly couplingthe platform to the chassis. The user may control the lift assembly toraise, lower, or otherwise move the platform through a user interfacecoupled to the platform. In some situations, it may be possible for anobstacle in the environment to push the user toward the user interfacewhile the lift assembly moves the platform. To limit or prevent this,the platform includes a user contact sensor positioned adjacent the userinterface. The user contact sensor includes a bar assembly having afirst end that is pivotally coupled to a rail. A second end of the barassembly is received within a bar aperture of a sensing portion that iscoupled to another rail. The bar assembly is positioned such that theupper body of the user will push against the bar assembly if the user isforced toward the user interface. This forces the second end of the barassembly out of the bar aperture. The sensing portion includes a sensorthat detects when the second end of the bar assembly is present withinthe bar aperture. In response to the sensor detecting that the bar hasexited the bar aperture, a controller stops or reverses movement of thelift device.

Lift Device

Referring to FIG. 1 , a lifting apparatus, lift device, or mobileelevating work platform (MEWP) (e.g., a telehandler, an electric boomlift, a towable boom lift, a lift device, a fully electric boom lift,etc.), shown as lift device 10 includes a base assembly 12 (e.g., abase, a support assembly, a drivable support assembly, a supportstructure, a chassis, etc.), a the platform assembly 16 (e.g., aplatform, a terrace, etc.), and a lift assembly 14 (e.g., a boom, a boomlift assembly, a lifting apparatus, an articulated arm, a scissors lift,etc.). The lift device 10 includes a front end (e.g., a forward facingend, a front portion, a front, etc.), shown as front 62, and a rear end(e.g., a rearward facing end, a back portion, a back, a rear, etc.,)shown as rear 60. The lift assembly 14 is configured to elevate theplatform assembly 16 in an upwards direction 46 (e.g., an upwardvertical direction) relative to the base assembly 12. The lift assembly14 is also configured to translate the platform assembly 16 in adownwards direction 48 (e.g., a downward vertical direction). The liftassembly 14 is also configured to translate the platform assembly 16 ineither a forwards direction 50 (e.g., a forward longitudinal direction)or a rearwards direction 51 (e.g., a rearward longitudinal direction).The lift assembly 14 generally facilitates performing a lifting functionto raise and lower the platform assembly 16, as well as movement of theplatform assembly 16 in various directions.

The base assembly 12 defines a longitudinal axis 78 and a lateral axis80. The longitudinal axis 78 defines the forward direction 50 of liftdevice 10 and the rearward direction 51. The lift device 10 isconfigured to translate in the forward direction 50 and to translatebackwards in the rearward direction 51. The base assembly 12 includesone or more wheels, tires, wheel assemblies, tractive elements, rotaryelements, treads, etc., shown as tractive elements 82. The tractiveelements 82 are configured to rotate to drive (e.g., propel, translate,steer, move, etc.) the lift device 10. The tractive elements 82 can eachinclude an electric motor 52 (e.g., electric wheel motors) configured todrive the tractive elements 82 (e.g., to rotate tractive elements 82 tofacilitation motion of the lift device 10). In other embodiments, thetractive elements 82 are configured to receive power (e.g., rotationalmechanical energy) from electric motors 52 or through a drive train(e.g., a combination of any number and configuration of a shaft, anaxle, a gear reduction, a gear train, a transmission, etc.). In someembodiments, one or more tractive elements 82 are driven by a primemover 41 (e.g., electric motor, internal combustion engine, etc.)through a transmission. In some embodiments, a hydraulic system (e.g.,one or more pumps, hydraulic motors, conduits, valves, etc.) transferpower (e.g., mechanical energy) from one or more electric motors 52and/or the prime mover 41 to the tractive elements 82. The tractiveelements 82 and electric motors 52 (or prime mover 41) can facilitate adriving and/or steering function of the lift device 10.

With additional reference to FIG. 4 , the platform assembly 16 is shownin further detail. The platform assembly 16 is configured to provide awork area for an operator of the lift device 10 to stand/rest upon. Theplatform assembly 16 can be pivotally coupled to an upper end of thelift assembly 14. The lift device 10 is configured to facilitate theoperator accessing various elevated areas (e.g., lights, platforms, thesides of buildings, building scaffolding, trees, power lines, etc.). Thelift device 10 may use various electrically-powered motors andelectrically-powered linear actuators or hydraulic cylinders tofacilitate elevation and/or horizontal movement (e.g., lateral movement,longitudinal movement) of the platform assembly 16 (e.g., relative tothe base assembly 12, or to a ground surface that the base assembly 12rests upon).

The platform assembly 16 includes a base member, a base portion, aplatform, a standing surface, a shelf, a work platform, a floor, a deck,etc., shown as a deck 18. The deck 18 provides a space (e.g., a floorsurface) for a worker to stand upon as the platform assembly 16 israised and lowered.

The platform assembly 16 includes a railing assembly including variousmembers, beams, bars, guard rails, rails, railings, etc., shown as rails22. The rails 22 extend along substantially an entire perimeter of thedeck 18. The rails 22 provide one or more members for the operator ofthe lift device 10 to grasp while using the lift device 10 (e.g., tograsp while operating the lift device 10 to elevate the platformassembly 16). The rails 22 can include members that are substantiallyhorizontal to the deck 18. The rails 22 can also include verticalstructural members that couple with the substantially horizontalmembers. The vertical structural members can extend upwards from thedeck 18.

The platform assembly 16 can include a human machine interface (HMI)(e.g., a user interface, an operator interface, etc.), shown as the userinterface 20. The user interface 20 is configured to receive user inputsfrom the operator at or upon the platform assembly 16 to facilitateoperation of the lift device 10. The user interface 20 can include anynumber of buttons, levers, switches, keys, etc., or any other user inputdevice configured to receive a user input to operate the lift device 10.The user interface 20 may also provide information to the user (e.g.,through one or more displays, lights, speakers, haptic feedback devices,etc.). The user interface 20 can be supported by one or more of therails 22.

Referring to FIG. 1 , the platform assembly 16 includes a frame 24(e.g., structural members, support beams, a body, a structure, etc.)that extends at least partially below the deck 18. The frame 24 can beintegrally formed with the deck 18. The frame 24 is configured toprovide structural support for the deck 18 of the platform assembly 16.The frame 24 can include any number of structural members (e.g., beams,bars, I-beams, etc.) to support the deck 18. The frame 24 couples theplatform assembly 16 with the lift assembly 14. The frame 24 may berotatably or pivotally coupled with the lift assembly 14 to facilitaterotation of the platform assembly 16 about an axis 28 (e.g., a verticalaxis). The frame 24 can also rotatably/pivotally couple with the liftassembly 14 such that the frame 24 and the platform assembly 16 canpivot about an axis 25 (e.g., a horizontal axis).

The lift assembly 14 includes one or more beams, articulated arms, bars,booms, arms, support members, boom sections, cantilever beams, etc.,shown as lift arms 32 a, 32 b, and 32 c. The lift arms are hingedly orrotatably coupled with each other at their ends. The lift arms can behingedly or rotatably coupled to facilitate articulation of the liftassembly 14 and raising/lowering and/or horizontal movement of theplatform assembly 16. The lift device 10 includes a lower lift arm 32 a,a central or medial lift arm 32 b, and an upper lift arm 32 c. The lowerlift arm 32 a is configured to hingedly or rotatably couple at one endwith the base assembly 12 to facilitate lifting (e.g., elevation) of theplatform assembly 16. The lower lift arm 32 a is configured to hingedlyor rotatably couple at an opposite end with the medial lift arm 32 b.Likewise, the medial lift arm 32 b is configured to hingedly orrotatably couple with the upper lift arm 32 c. The upper lift arm 32 ccan be configured to hingedly interface/couple and/or telescope with anintermediate lift arm 32 d. The upper lift arm 32 c can be referred toas “the jib” of the lift device 10. The intermediate lift arm 32 d mayextend into an inner volume of the upper lift arm 32 c and extend and/orretract. The lower lift arm 32 a and the medial lift arm 32 b may bereferred to as “the boom” of the overall lift device 10 assembly. Theintermediate lift arm 32 d can be configured to couple (e.g., rotatably,hingedly, etc.), with the platform assembly 16 to facilitate levellingof the platform assembly 16.

The lift arms 32 are driven to hinge or rotate relative to each other byactuators 34 a, 34 b, 34 c, and 34 d (e.g., electric linear actuators,linear electric arm actuators, hydraulic cylinders, etc.). The actuators34 a, 34 b, 34 c, and 34 d can be mounted between adjacent lift arms todrive adjacent lift arms to hinge or pivot (e.g., rotate some angularamount) relative to each other about pivot points 84. The actuators 34a, 34 b, 34 c, and 34 d can be mounted between adjacent lift arms usingany of a foot bracket, a flange bracket, a clevis bracket, a trunnionbracket, etc. The actuators 34 a, 34 b, 34 c, and 34 d may be configuredto extend or retract (e.g., increase in overall length, or decrease inoverall length) to facilitate pivoting adjacent lift arms to pivot/hingerelative to each other, thereby articulating the lift arms and raisingor lowering the platform assembly 16.

The actuators 34 a, 34 b, 34 c, and 34 d can be configured to extend(e.g., increase in length) to increase a value of an angle formedbetween adjacent lift arms 32. The angle can be defined betweencenterlines of adjacent lift arms 32 (e.g., centerlines that extendsubstantially through a center of the lift arms 32). For example, theactuator 34 a is configured to extend/retract to increase/decrease theangle 74 a defined between a centerline of the lower lift arm 32 a andthe longitudinal axis 78 (angle 74 a can also be defined between thecenterline of the lower lift arm 32 a and a plane defined by thelongitudinal axis 78 and lateral axis 80) and facilitate lifting of theplatform assembly 16 (e.g., moving the platform assembly 16 at leastpartially along the upward direction 46). Likewise, the actuator 34 bcan be configured to retract to decrease the angle 74 a to facilitatelowering of the platform assembly 16 (e.g., moving the platform assembly16 at least partially along the downward direction 48). Similarly, theactuator 34 b is configured to extend to increase the angle 74 b definedbetween centerlines of the lower lift arm 32 a and the medial lift arm32 b and facilitate elevating of the platform assembly 16. Similarly,the actuator 34 b is configured to retract to decrease the angle 74 b tofacilitate lowering of the platform assembly 16. The electric actuator34 c is similarly configured to extend/retract to increase/decrease theangle 74 c, respectively, to raise/lower the platform assembly 16.

The actuators 34 a, 34 b, 34 c, and 34 d can be mounted (e.g., rotatablycoupled, pivotally coupled, etc.) to adjacent lift arms at mounts 40(e.g., mounting members, mounting portions, attachment members,attachment portions, etc.). The mounts 40 can be positioned at anyposition along a length of each lift arm. For example, the mounts 40 canbe positioned at a midpoint of each lift arm, and a lower end of eachlift arm.

The intermediate lift arm 32 d and the frame 24 are configured topivotally interface/couple at a platform rotator 30 (e.g., a rotaryactuator, a rotational electric actuator, a gear box, etc.). Theplatform rotator 30 facilitates rotation of the platform assembly 16about the axis 28 relative to the intermediate lift arm 32 d. In someembodiments, the platform rotator 30 is positioned between the frame 24and the upper lift arm 32 c and facilitates pivoting of the platformassembly 16 relative to the upper lift arm 32 c. The axis 28 extendsthrough a central pivot point of the platform rotator 30. Theintermediate lift arm 32 d can also be configured to articulate or bendsuch that a distal portion of the intermediate lift arm 32 dpivots/rotates about the axis 25. The intermediate lift arm 32 d can bedriven to rotate/pivot about axis 25 by extension and retraction of theactuator 34 d.

The intermediate lift arm 32 d is also configured to extend/retract(e.g., telescope) along the upper lift arm 32 c. In some embodiments,the lift assembly 14 includes a linear actuator (e.g., a hydrauliccylinder, an electric linear actuator, etc.), shown as extensionactuator 35, that controls extension and retraction of the intermediatelift arm 32 d relative to the upper lift arm 32 c. In other embodiments,one more of the other arms of the lift assembly 14 include multipletelescoping sections that are configured to extend/retract relative toone another.

The platform assembly 16 is configured to be driven to pivot about theaxis 28 (e.g., rotate about axis 28 in either a clockwise or acounter-clockwise direction) by an electric or hydraulic motor 26 (e.g.,a rotary electric actuator, a stepper motor, a platform rotator, aplatform electric motor, an electric platform rotator motor, etc.). Themotor 26 can be configured to drive the frame 24 to pivot about the axis28 relative to the upper lift arm 32 c (or relative to the intermediatelift arm 32 d). The motor 26 can be configured to drive a gear train topivot the platform assembly 16 about the axis 28.

Referring to FIGS. 1 and 2 , the lift assembly 14 is configured topivotally or rotatably couple with the base assembly 12. The baseassembly 12 includes a rotatable base member, a rotatable platformmember, a fully electric turntable, etc., shown as a turntable 70. Thelift assembly 14 is configured to rotatably/pivotally couple with thebase assembly 12. The turntable 70 is rotatably coupled with a base,frame, structural support member, carriage, etc., of base assembly 12,shown as base 36. The turntable 70 is configured to rotate or pivotrelative to the base 36. The turntable 70 can pivot/rotate about thecentral axis 42 relative to base 36, about a slew bearing 71 (e.g., theslew bearing 71 pivotally couples the turntable 70 to the base 36). Theturntable 70 facilitates accessing various elevated and angularly offsetlocations at the platform assembly 16. The turntable 70 is configured tobe driven to rotate or pivot relative to base 36 and about the slewbearing 71 by an electric motor, an electric turntable motor, anelectric rotary actuator, a hydraulic motor, etc., shown as theturntable motor 44. The turntable motor 44 can be configured to drive ageared outer surface 73 of the slew bearing 71 that is rotatably coupledto the base 36 about the slew bearing 71 to rotate the turntable 70relative to the base 36. The lower lift arm 32 a is pivotally coupledwith the turntable 70 (or with a turntable member 72 of the turntable70) such that the lift assembly 14 and the platform assembly 16 rotateas the turntable 70 rotates about the central axis 42. In someembodiments, the turntable 70 is configured to rotate a complete 360degrees about the central axis 42 relative to the base 36. In otherembodiments, the turntable 70 is configured to rotate an angular amountless than 360 degrees about the central axis 42 relative to the base 36(e.g., 270 degrees, 120 degrees, etc.).

The base assembly 12 includes one or more energy storage devices orpower sources (e.g., capacitors, batteries, Lithium-Ion batteries,Nickel Cadmium batteries, fuel tanks, etc.), shown as batteries 64. Thebatteries 64 are configured to store energy in a form (e.g., in the formof chemical energy) that can be converted into electrical energy for thevarious electric motors and actuators of the lift device 10. Thebatteries 64 can be stored within the base 36. The lift device 10includes a controller 38 that is configured to operate any of themotors, actuators, etc., of the lift device 10. The controller 38 can beconfigured to receive sensory input information from various sensors ofthe lift device 10, user inputs from the user interface 20 (or any otheruser input device such as a key-start or a push-button start), etc. Thecontroller 38 can be configured to generate control signals for thevarious motors, actuators, etc., of the lift device 10 to operate any ofthe motors, actuators, electrically powered movers, etc., of the liftdevice 10. The batteries 64 are configured to power any of the motors,sensors, actuators, electric linear actuators, electrical devices,electrical movers, stepper motors, etc., of the lift device 10. The baseassembly 12 can include a power circuit including any necessarytransformers, resistors, transistors, thermistors, capacitors, etc., toprovide appropriate power (e.g., electrical energy with appropriatecurrent and/or appropriate voltage) to any of the motors, electricactuators, sensors, electrical devices, etc., of the lift device 10.

The batteries 64 are configured to deliver power to the motors 52 todrive the tractive elements 82. A rear set of tractive elements 82 canbe configured to pivot to steer the lift device 10. In otherembodiments, a front set of tractive elements 82 are configured to pivotto steer the lift device 10. In still other embodiments, both the frontand the rear set of tractive elements 82 are configured to pivot (e.g.,independently) to steer the lift device 10. In some examples, the baseassembly 12 includes a steering system 150. The steering system 150 isconfigured to drive tractive elements 82 to pivot for a turn of the liftdevice 10. The steering system 150 can be configured to pivot thetractive elements 82 in pairs (e.g., to pivot a front pair of tractiveelements 82), or can be configured to pivot tractive elements 82independently (e.g., four-wheel steering for tight-turns).

In some embodiments, the base assembly 12 also includes a user interface21 (e.g., a HMI, a user interface, a user input device, a displayscreen, etc.). In some embodiments, the user interface 21 is coupled tothe base 36. In other embodiments, the user interface 21 is positionedon the turntable 70. The user interface 21 can be positioned on any sideor surface of the base assembly 12 (e.g., on the front 62 of the base36, on the rear 60 of the base 36, etc.)

Referring now to FIGS. 2 and 3 , the base assembly 12 includes alongitudinally extending frame member 54 (e.g., a rigid member, astructural support member, an axle, a base, a frame, a carriage, achassis, etc.). The longitudinally extending frame member 54 providesstructural support for the turntable 70 as well as the tractive elements82. The longitudinally extending frame member 54 is pivotally coupledwith lateral frame members 110 (e.g., axles, frame members, beams, bars,etc.) at opposite longitudinal ends of the longitudinally extendingframe member 54. For example, the lateral frame members 110 may bepivotally coupled with the longitudinally extending frame member 54 at afront end and a rear end of the longitudinally extending frame member54. The lateral frame members 110 can each be configured to pivot abouta pivot joint 58 (e.g., about a longitudinal axis). The pivot joint 58can include a pin and a receiving portion (e.g., a bore, an aperture,etc.). The pin of the pivot joint 58 is coupled to one of the lateralframe members 110 (e.g., a front lateral frame member 110 or a rearlateral frame member 110) or the longitudinally extending frame member54 and the receiving portion is coupled to the other of thelongitudinally extending frame member 54 and the lateral frame member110. For example, the pin may be coupled with longitudinally extendingframe member 54 and the receiving portion can be coupled with one of thelateral frame members 110 (e.g., integrally formed with the frontlateral frame member 110).

In some embodiments, the longitudinally extending frame member 54 andthe lateral frame members 110 are integrally formed or coupled (e.g.,fastened, welded, riveted, etc.) to define the base 36. In still otherembodiments, the base 36 is integrally formed with the longitudinallyextending frame member 54 and/or the lateral frame members 110. In stillother embodiments, the base 36 is coupled with the longitudinallyextending frame member 54 and/or the lateral frame members 110.

The base assembly 12 includes one or more axle actuators 56 (e.g.,electric linear actuators, electric axle actuators, electric levellingactuators, hydraulic cylinders, etc.). The axle actuators 56 can belinear actuators configured to receive power from the batteries 64, forexample. The axle actuators 56 can be configured to extend or retract tocontact a top surface of a corresponding one of the lateral framemembers 110. When the axle actuators 56 extend, an end of a rod of thelevelling actuators can contact the surface of lateral frame member 110and prevent relative rotation between lateral frame member 110 andlongitudinally extending frame member 54. In this way, the relativerotation/pivoting between the lateral frame member 110 and thelongitudinally extending frame member 54 can be locked (e.g., to preventrolling of the longitudinally extending frame member 54 relative to thelateral frame members 110 during operation of the lift assembly 14). Theaxle actuators 56 can receive power from the batteries 64, which canallow the axle actuators 56 to extend or retract. The axle actuators 56receive control signals from controller 38.

Control System

Referring to FIG. 5 , the lift device 10 includes a control system 200.The control system 200 includes the controller 38. The controller 38includes a processor 202 and a memory device, shown as memory 204. Thememory 204 may contain one or more programs or instructions forexecution by the processor 202.

As shown in FIG. 5 , the controller 38 is operatively coupled to (e.g.,in communication with) the motor 26, the platform rotator 30, theturntable motor 44, the actuators (e.g., the actuator 34 a, the actuator34 b, etc.), the extension actuator 35, and the motors 52. Thecontroller 38 is operatively coupled to the user interface 20 and theuser interface 21. The controller 38 is operatively coupled to anindicator, shown as alarm 210. The alarm 210 may provide an indication,alert, or warning to a user when activated. The indication from thealarm 210 may be visual, auditory, or another type of indication (e.g.,vibrational haptic feedback). By way of example, the alarm 210 mayprovide an auditory indication (e.g., a siren) or a visual indication(e.g., a flashing light) to a user. The controller 38 is operativelycoupled to a sensor assembly (e.g., a barrier sensor, an operatorposition sensor, a user position sensor, a user contact sensor, anoperator contact sensor, etc.), shown as user contact sensor 300. Asdescribed herein, the user contact sensor 300 is configured to providean indication (e.g., a signal) to the controller 38 in response tocontact with a user. The user contact sensor 300 may be positioned suchthat a user positioned in front of the user contact sensor 300 engagesthe user contact sensor 300 when a portion of a user's upper body (e.g.,a torso, a stomach, a shoulder, etc.) moves toward and/or above the userinterface 20. Although FIG. 5 only illustrates operative couplingbetween the controller 38 and certain components of the lift device 10,it should be understood that other components may be in communicationwith the controller 38 as well. By way of example, the batteries 64 maybe operatively coupled to the controller 38.

The controller 38 may be configured to receive information (e.g., userinstructions, sensor signals, etc.) from one or more components of thelift device 10. By way of example, the controller 38 may receive userinputs or commands from the user interface 20 and/or the user interface21. By way of another example, the controller 38 may receive an inputfrom the user contact sensor 300 (e.g., a signal indicating that a userhas applied a force on the user contact sensor 300).

The controller 38 may be configured to provide information (e.g.,commands, indication, etc.) to one or more components of the lift device10. By way of example, the controller 38 may send commands (e.g.,signals) that control the outputs (e.g., movement) of the motor 26, theactuators 34, the extension actuator 35, the motors 52, and/or any otheractuators of the lift device 10. By way of another example, thecontroller 38 may provide a command to the alarm 210 that causes thealarm 210 to activate. By way of another example, the controller 38 mayprovide commands that cause the user interface 20 and/or the userinterface 21 to provide (e.g., display) information to a user.

User Contact Sensor

Referring to FIGS. 4 and 6-9 , the user contact sensor 300 is coupled tothe rails 22. Specifically, the rails 22 include a pair of framemembers, shown as vertical rails 302, that extend vertically upward fromthe deck 18. The vertical rails 302 are positioned on opposite sides ofthe user interface 20 such that the user interface 22 extends laterallybetween the vertical rails 302. A rail, shown as cage 310, is fixedlycoupled to the vertical rails 302 and extends around the user interface20. Specifically, the cage 310 extends laterally between the verticalrails 302, longitudinally forward of the vertical rails 302, andlongitudinally rearward of the vertical rails 302. The cage 310 includesa pair of inclined portions 312, each extending longitudinally forwardand vertically upward from a middle portion of one of the vertical rails302. The cage 310 further includes a pair of curved portions 314, eachcoupled to an upper end of one of the inclined portions 312. The curvedportions 314 each extend upward and longitudinally rearward from thecorresponding inclined portion 312. A u-shaped horizontal portion 316 iscoupled to both of the curved portions 314. The horizontal portion 316extends longitudinally rearward from the curved portions 314 andlaterally between the curved portions 314. The horizontal portion 316 iscoupled to the top end of each vertical rail 302. The curved portions314 and the horizontal portion 316 both extend above the user interface20.

The user contact sensor 300 is an assembly including a first end portionor hinge, shown as pivot portion 320, a second end portion, shown assensing portion 322, and central portion or rod, shown as bar assembly324. The pivot portion 320 is directly coupled to the curved portion 314of the cage 310 on the left side of the user interface 20. The sensingportion 322 is directly coupled to the curved portion 314 of the cage310 on the right side of the user interface 20. The bar assembly 324 iscoupled to the pivot portion 320 and extends laterally from the pivotportion 320 to the sensing portion 322. Accordingly, the user contactsensor 300 is positioned above and longitudinally forward of the userinterface 20. In other embodiments, the user contact sensor 300 ismirrored such that the sensing portion 322 is positioned to the left ofthe user interface 20 and the pivot portion 320 is positioned to theright of the user interface.

Referring to FIGS. 8, 10, 11, and 14 , the pivot portion 320 is shownaccording to an exemplary embodiment. The pivot portion 320 includes afirst bracket, first hinge portion, or pivoting portion, shown aspivoting clevis 330, and a second bracket, second hinge portion, orfixed portion, shown as fixed clevis 332. The fixed clevis 332 isfixedly coupled to the curved portion 314 to the left of the userinterface 20. The pivoting clevis 330 is pivotally coupled to the fixedclevis 332 such that the pivoting clevis 330 pivots about an axis 334.Specifically, a pair of fasteners, shown as bolts 336, extend throughcorresponding pivot apertures defined by the pivoting clevis 330 and thefixed clevis 332 to pivotally couple the pivoting clevis 330 to thefixed clevis 332. In some embodiments, the axis 334 is skewed in alongitudinal direction relative to a vertical axis such that the barassembly 334 moves downward when moved in a longitudinally rearwarddirection. In other embodiments, the axis 334 is substantially vertical.The pivoting clevis 330 further defines an aperture or passage (e.g., arod aperture), shown as bar aperture 338, that extends perpendicular tothe axis 334. The bar aperture 338 receives the bar assembly 324therethrough.

Referring to FIGS. 9, 10, 12, and 13 , the sensing portion 322 is shownaccording to an exemplary embodiment. The sensing portion 322 includes ahousing 340. The housing 340 includes a first member or face plateportion, shown as outer plate 342, and defines a surface of the housing340 that faces the pivot portion 320. The outer plate 342 defines alaterally-extending aperture or passage, shown as end aperture 344. Theend aperture 344 is sized to receive an end of the bar assembly 324. Theouter plate 342 is directly coupled to a second member or portion of thehousing 340, shown as inner plate 346. The inner plate 346 and the outerplate 342 may extend substantially parallel to one another. The innerplate 346 defines a laterally-extending aperture or passage, shown assensor aperture 348. The sensor aperture 348 may be substantiallyaligned with the end aperture 344. The housing 348 further includes athird member, shown as back shell 350. The back shell 350 is coupled tothe inner plate 346 and the outer plate 342. An inner volume of thehousing 350 is defined between the inner plate 346 and the back shell350.

The inner volume of the housing 350 receives a sensor 360 extending intothe sensor aperture 348. The sensor 360 may be substantially alignedwith the end aperture 344 and the sensor aperture 348. The sensor 360 isreceived within a laterally-extending passage or aperture defined by aboss, shown as sensor block 362. The sensor block 362 is coupled to theinner plate 346. In some embodiments, the lateral position of the sensor360 relative to the sensor block 362 is adjustable (e.g., the sensor 360is selectively slidably coupled to the block 360 of the housing 360). Asshown in FIG. 13 , the sensing portion 322 includes a pair of fasteners,shown as sensor bolts 364, that are in threaded engagement with thesensor block 362. The sensor bolts 364 may be loosened to permit freelateral movement of the sensor 360. When tightened, the sensor bolts 364engage the sensor 360, limiting (e.g., preventing) lateral movement ofthe sensor 360.

Referring to FIGS. 8-11 and 13-17 , the bar assembly 324 is shownaccording to an exemplary embodiment. The bar assembly 324 includes afirst portion, central portion, or resilient member, shown as bar 370.The bar 370 is relatively long and thin and makes up the majority of thelength of the bar assembly 324. In some embodiments, the bar 370 is madefrom a resilient material that is flexible but returns to an originalshape after an applied force on the bar 370 is released. In oneembodiment, the bar 370 may be made from fiberglass. In otherembodiments, the bar 370 is made from another resilient material, suchas plastic.

Coupled to a first end of the bar 370 is a first end portion of the barassembly 324, shown as threaded end 372. The threaded end 372 is fixedlycoupled to the bar 370. By way of example, the threaded end 372 maydefine a recess that receives an end of the bar 370, and the bar 370 maybe fixed in place using an adhesive (e.g., epoxy). The threaded end 372includes exterior threads, shown as threaded portion 374. The threadedportion 374 extends through the bar aperture 338 defined by the pivotportion 320. A pair of fasteners, shown as nuts 376, each engage thethreaded portion 374. Specifically, each nut 376 is positioned on andtightened against an opposing side of the pivoting clevis 330, holdingthe threaded end 372 in place relative to the pivoting clevis 330. Thelateral position of the threaded end 372 relative to the pivoting clevis330 may be adjusted (e.g., to adjust the position of the opposing endrelative to the sensing portion 322) by loosening the nuts 376, movingthe nuts 376 to a different position along the threaded portion 374, andretightening the nuts 376. In other embodiments, the bar aperture 338 isin threaded engagement with the threaded portion 374. In suchembodiments, one or both of the nuts 376 may be omitted.

Coupled to a second end of the bar 370 opposite the first end is asecond end portion of the bar assembly 324, shown as sensor end 380. Thesensor end 380 is fixedly coupled to the bar 370. By way of example, thesensor end 380 may define a recess that receives an end of the bar 370,and the bar 370 may be fixed in place using an adhesive. The sensor end380 is sized to be received within the end aperture 344. The exteriorsurface of the sensor end 380 may be substantially cylindrical. In otherembodiments, the sensor end 380 formed as part of the bar 370 (i.e., thebar 370 and the sensor end 380 are not separate pieces).

The sensor 360 is operatively coupled to the controller 38 andconfigured to provide a signal indicating at least one of (a) whether ornot the sensor end 380 is present within the end aperture 344 or (b)that the sensor end 380 has entered or exited the end aperture 344. Byway of example, the sensor 360 may indicate that the sensor end 380 hasexited the end aperture 344 when the sensor 360 detects the presence ofthe sensor end 380 at a first time and subsequently does not detect thepresence of the sensor end 380. The sensor 360 may be or include anytype of sensor that is capable of providing this information.

In some embodiments, the sensor 360 is a proximity sensor that isconfigured to detect a proximity of an object within the end aperture344. In such an embodiment, the sensor 360 may determine that the sensorend 380 is present when the sensor 360 detects an object within athreshold distance of the sensor 360. In such embodiments, the nuts 376and/or the fasteners 364 may be adjusted to adjust the lateral positionsof the sensor 360 and/or the bar assembly 324, thereby varying thedistance between the sensor end 380 and the sensor 360. This adjustmentmay be performed such that the sensor end 380 is positioned within thethreshold distance of the sensor 360 when the sensor end 380 is receivedwithin the end aperture 344. In some embodiments that utilize aproximity sensor, the sensor 360 is spaced or separated from the sensorend 380 such that the sensor end 380 does not engage the sensor 360.

In some embodiments, the sensor 360 is a proximity sensor that isconfigured to sense the presence of metals (e.g., an inductive proximitysensor). Such a proximity sensor may be configured to differentiate ordistinguish between a metal or metallic material (e.g., steel, brass,aluminum, copper, etc.) and a non-metal or non-metallic material (e.g.,plastic, fiberglass, wood, etc.). By way of example, the sensor 360 mayprovide a first signal in response to the presence of a metal within thethreshold distance and provide a second, different signal in response tothe presence of a non-metal within the threshold distance. Inembodiments that utilize a proximity sensor that is configured to sensemetals, the sensor end 380 may be made of a metal, and the portions ofthe housing 350 that are in close proximity to the sensor 360 (e.g., theouter plate 340 and the inner plate 346) may be made of a non-metal.Such a configuration may facilitate avoiding falsely detecting thepresence of the sensor end 380.

In other embodiments, the sensor 360 utilizes a different type ofsensor. In some embodiments, the sensor 360 utilizes a different type ofproximity sensor. By way of example, the sensor 360 may include aninfrared proximity sensor, an ultrasonic proximity sensor, a capacitiveproximity sensor, a laser rangefinder, or another type of proximitysensor. In some embodiments, a permanent magnet is coupled to the sensorend 380, and a sensor 360 (e.g., a hall effect sensor) detects themagnetic field produced by the permanent magnet. In some embodiments,the sensor 360 includes a break beam sensor that detects when a beam oflight is interrupted by the sensor end 380. Such a sensor may bepositioned such that the sensor end 380 interrupts the beam when thesensor end 380 is received within the end aperture 344. In someembodiments, the sensor 360 includes two more contacts that engage thesensor end 380, passing current through the sensor 380. Such as sensormay be positioned such that the sensor end 380 engages the contacts toform a closed circuit within the sensor end 380 is received within theend aperture 344, and the controller 348 whether or not the sensor end380 is present based on a measured current passing through the contacts.

Operation of the user contact sensor 300 is shown from a firstperspective in FIGS. 18-21 and from a second perspective in FIGS. 22-24. In operation, the user contact sensor 300 is configured such that thesensor end 380 is normally positioned within the end aperture 344. Thisconfiguration is shown in FIGS. 18 and 22 . The rails 22 hold the pivotportion 320 and the sensing portion 322 at a fixed distance relative toone another, and the bar is sized such that the sensor end 380 engagesthe outer plate 342 to prevent the sensor end 380 from leaving the endaperture 344 due to minor forces (e.g., due to vibration of the liftdevice 10, due to a user brushing against the bar 370, etc.). While thesensor end 380 remains within the end aperture 344, the sensor 360provides a first signal to the controller 38, and the controller 38permits standard control of the lift device 10.

As the user operates the lift device 10, they generally stand in frontof the user interface 20 and face toward the user interface 20, as shownin FIGS. 18 and 22 . In some situations, the lift assembly 14, theturntable 70, and/or the motors 52 move the platform 16 in proximity toan obstacle (e.g., a tree, a portion of a structure such as a supportbeam, etc.). In some such situations, the user is positioned between theuser interface 20 and the obstacle. As the lift assembly 14 moves theplatform 16, the distance between the user interface 20 and the obstaclemay decrease, limiting the freedom of movement of the operator. In somesuch cases, it may be difficult for the user to access the controls ofthe user interface 20 to move the platform 16 away from the obstacle.

If the obstacle pushes the user toward the user interface 20, the usercomes into contact with the bar 370 of the user contact sensor 300. Insome embodiments, the height of the bar 370 is selected such that theupper body (e.g., the stomach, the chest, the arms, the shoulders, etc.)of the user comes into contact with the bar 370. As shown in FIGS. 19and 23 , the user presses against the bar 370, applying alongitudinally-rearward force near the center of the bar 370, and theresilient material of the bar 370 begins to bow. If the user were torelease the force on the bar 370, the resilient material of the bar 370would return to the original, straight shape, and the sensor end 380would remain in the end aperture 344 (e.g., the bar 370 elasticallydeforms in response to the force on the bar 370). Accordingly, theresilient nature of the bar 370 causes the bar 370 to apply a biasingforce that resists (a) bending of the bar 370 and (b) removal of thesensor end 380 from the end aperture 344. If the user's force on the bar370 is released before the bow 370 is bent to a threshold position, thebiasing force of the bar 370 returns the bar 370 and the sensor end 380to the original position.

As shown in FIGS. 20 and 24 , if the user continues to apply a force onthe bar 370 (e.g., because they are being pushed rearward by the objectas the lift assembly 14 extends), the bending of the bar 370 becomessignificant enough (e.g., exceeds a threshold deflection, is bent beyondthe threshold position, etc.) for the sensor end 380 to exit the endaperture 344. After the sensor end 380 exits the end aperture 344, thepivot portion 320 permits the bar 370 to rotate freely away from theuser, longitudinally rearward and/or downward.

In response to the sensor end 380 exiting the end aperture 344, thesensor 360 provides a second signal to the controller 38. The secondsignal indicates that the sensor end 380 has exited the end aperture344. In response to receiving the second signal, the controller 38 maybe configured to perform one or more actions to stop or reverse one ormore recent movements of the lift device 10. The controller 38 mayadditionally or alternatively activate the alarm 210 in response toreceiving the second signal. By way of example, the controller 38 maystop movement of all of the actuators of the lift device 10 (e.g., theactuators 34, the motors 32, etc.). By taking this action, thecontroller 38 may ensure that the platform 16 does not move furtherrelative to the obstacle.

In some embodiments, in response to receiving the second signal, thecontroller 38 is configured to reverse the movements of one or moresystems of the lift device 10 that occurred immediately before thesecond signal was received. One such example of this is illustrated inFIGS. 18-21 . In FIGS. 18 and 19 , the platform 16 rises. After the usercontact sensor 300 is activated in FIG. 20 , the platform 16 is loweredin FIG. 21 . By way of another example, if the lift assembly 14 raisedthe platform 16 and the motors 52 moved the base assembly 12 in aforward direction immediately prior to the receipt of the second signal,the controller 38 may control the lift assembly 14 to lower the platform16 and/or control the motors 52 to move the base assembly 12 in areverse direction. In order to identify the correct reverse movements toperform, the controller 38 may retain a history of all of the movementsof the lift device 10 (e.g., as measured by sensors or as instructed bythe controller 38) and the time at which they occurred. The controller38 may determine what reverse movements to perform based on the history.

Referring to FIGS. 25-30 , an alternative embodiment of the platform 16and the user contact sensor 300 is shown according to an exemplaryembodiment. The platform 16 and the user contact sensor 300 may besubstantially similar to the platform 16 and the user contact sensor 300as previously described, except as otherwise specified.

The platform 16 of FIG. 25 includes a pair of rails, shown as uprightrails 400 and 402. The upright rails 400 and 402 extend generallyvertically. The user interface 20 is contained within a cover, shown ashousing 410, that is fixedly coupled to the upright rails 400 and 402.The upright rail 400 is positioned laterally to the left of the userinterface 20 and the housing 410. The upright rail 402 is positionedlaterally to the right of the user interface 20 and the housing 410.Accordingly, the user interface 20 and the housing 410 extend laterallybetween the upright rails 400 and 402.

The user contact sensor 300 of FIG. 25 includes a pivot portion 420, asensing portion 422, and a bar assembly 424 that may be substantiallysimilar to the pivot portion 320, the sensing portion 322, and the barassembly 324, respectively, except as otherwise specified. As shown inFIGS. 25-28 , the pivot portion 420 is coupled to an upper end portionof the upright rail 400. Specifically, the fixed clevis 332 is fixedlycoupled to the upright rail 400. The sensing portion 422 is coupled toan upper end portion of the upright rail 402.

As shown in FIGS. 28 and 29 , in the sensing portion 424, the sensor 360is omitted and replaced with a microswitch or contacting switch, shownas switch assembly 460. The switch assembly 460 includes a main body,shown as switch body 462, and an interface or interface member, shown asbutton 464. The button 464 is positioned in alignment with the endaperture 344 such that the sensor end 380 of the bar assembly 424engages the button 464 when the sensor end 380 is positioned within theend aperture 344. The button 464 is configured to move along a lateralaxis 466. Accordingly, when sensor end 380 is positioned within the endaperture 344, the button 464 is depressed, activating the switchassembly 460. The switch assembly 460 may communicate similar signalswith the controller 38 as the sensor 360. By way of example, the switchassembly 460 may provide a first signal to the controller 38 when thebutton 464 is depressed (i.e., the sensor end 380 is in the end aperture344) and a second signal when the button 464 is not depressed (i.e., thesensor end 380 is not in the end aperture 344) (e.g., an indication thatthe sensor end 380 has exited the end aperture 344).

Referring to FIG. 30 , a diagram of the switch assembly 460 is shownaccording to an exemplary embodiment. In other embodiments, the switchassembly 460 is otherwise configured. As shown, the button 464 of theswitch assembly 460 is biased away from a depressed position by abiasing element or biasing member, shown as spring 470. The switchassembly 460 includes a first switch 480 and a second switch 490 eachcoupled to the button 464. The first switch 480 includes contacts 482and 484. The second switch 490 includes contacts 492 and 494. In someembodiments, the contact 484 and the contact 492 are connected (e.g., toa common ground). The spring 470 biases both the switch 480 and theswitch 490 into a normally closed configuration.

During normal operation, the sensor end 380 depresses the button 464,holding the switch 480 and the switch 490 in an open configuration. Withboth the switch 480 and the switch 490 in the open configuration, theswitch assembly 460 provides the first signal. When the sensor end 380leaves the end aperture 344, the spring 470 forces the switch 480 andthe switch 490 to close. When one or both of the switch 480 and theswitch 490 read as closed, the switch assembly 460 provides the secondsignal. The use of two switches may ensure functionality of the switchassembly 460, even if one of the switches fails.

As utilized herein, the terms “approximately,” “about,” “substantially,”and similar terms are intended to have a broad meaning in harmony withthe common and accepted usage by those of ordinary skill in the art towhich the subject matter of this disclosure pertains. It should beunderstood by those of skill in the art who review this disclosure thatthese terms are intended to allow a description of certain featuresdescribed and claimed without restricting the scope of these features tothe precise numerical ranges provided. Accordingly, these terms shouldbe interpreted as indicating that insubstantial or inconsequentialmodifications or alterations of the subject matter described and claimedare considered to be within the scope of the disclosure as recited inthe appended claims.

It should be noted that the term “exemplary” and variations thereof, asused herein to describe various embodiments, are intended to indicatethat such embodiments are possible examples, representations, orillustrations of possible embodiments (and such terms are not intendedto connote that such embodiments are necessarily extraordinary orsuperlative examples).

The term “coupled” and variations thereof, as used herein, means thejoining of two members directly or indirectly to one another. Suchjoining may be stationary (e.g., permanent or fixed) or moveable (e.g.,removable or releasable). Such joining may be achieved with the twomembers coupled directly to each other, with the two members coupled toeach other using a separate intervening member and any additionalintermediate members coupled with one another, or with the two memberscoupled to each other using an intervening member that is integrallyformed as a single unitary body with one of the two members. If“coupled” or variations thereof are modified by an additional term(e.g., directly coupled), the generic definition of “coupled” providedabove is modified by the plain language meaning of the additional term(e.g., “directly coupled” means the joining of two members without anyseparate intervening member), resulting in a narrower definition thanthe generic definition of “coupled” provided above. Such coupling may bemechanical, electrical, or fluidic.

References herein to the positions of elements (e.g., “top,” “bottom,”“above,” “below”) are merely used to describe the orientation of variouselements in the FIGURES. It should be noted that the orientation ofvarious elements may differ according to other exemplary embodiments,and that such variations are intended to be encompassed by the presentdisclosure.

The hardware and data processing components used to implement thevarious processes, operations, illustrative logics, logical blocks,modules and circuits described in connection with the embodimentsdisclosed herein may be implemented or performed with a general purposesingle- or multi-chip processor, a digital signal processor (DSP), anapplication specific integrated circuit (ASIC), a field programmablegate array (FPGA), or other programmable logic device, discrete gate ortransistor logic, discrete hardware components, or any combinationthereof designed to perform the functions described herein. A generalpurpose processor may be a microprocessor, or, any conventionalprocessor, controller, microcontroller, or state machine. A processoralso may be implemented as a combination of computing devices, such as acombination of a DSP and a microprocessor, a plurality ofmicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration. In some embodiments, particularprocesses and methods may be performed by circuitry that is specific toa given function. The memory (e.g., memory, memory unit, storage device)may include one or more devices (e.g., RAM, ROM, Flash memory, hard diskstorage) for storing data and/or computer code for completing orfacilitating the various processes, layers and modules described in thepresent disclosure. The memory may be or include volatile memory ornon-volatile memory, and may include database components, object codecomponents, script components, or any other type of informationstructure for supporting the various activities and informationstructures described in the present disclosure. According to anexemplary embodiment, the memory is communicably connected to theprocessor via a processing circuit and includes computer code forexecuting (e.g., by the processing circuit or the processor) the one ormore processes described herein.

The present disclosure contemplates methods, systems and programproducts on any machine-readable media for accomplishing variousoperations. The embodiments of the present disclosure may be implementedusing existing computer processors, or by a special purpose computerprocessor for an appropriate system, incorporated for this or anotherpurpose, or by a hardwired system. Embodiments within the scope of thepresent disclosure include program products comprising machine-readablemedia for carrying or having machine-executable instructions or datastructures stored thereon. Such machine-readable media can be anyavailable media that can be accessed by a general purpose or specialpurpose computer or other machine with a processor. By way of example,such machine-readable media can comprise RAM, ROM, EPROM, EEPROM, orother optical disk storage, magnetic disk storage or other magneticstorage devices, or any other medium which can be used to carry or storedesired program code in the form of machine-executable instructions ordata structures and which can be accessed by a general purpose orspecial purpose computer or other machine with a processor. Combinationsof the above are also included within the scope of machine-readablemedia. Machine-executable instructions include, for example,instructions and data which cause a general purpose computer, specialpurpose computer, or special purpose processing machines to perform acertain function or group of functions.

Although the figures and description may illustrate a specific order ofmethod steps, the order of such steps may differ from what is depictedand described, unless specified differently above. Also, two or moresteps may be performed concurrently or with partial concurrence, unlessspecified differently above. Such variation may depend, for example, onthe software and hardware systems chosen and on designer choice. Allsuch variations are within the scope of the disclosure. Likewise,software implementations of the described methods could be accomplishedwith standard programming techniques with rule-based logic and otherlogic to accomplish the various connection steps, processing steps,comparison steps, and decision steps.

It is important to note that the construction and arrangement of thelift device 10 as shown in the various exemplary embodiments isillustrative only. Additionally, any element disclosed in one embodimentmay be incorporated or utilized with any other embodiment disclosedherein. Although only one example of an element from one embodiment thatcan be incorporated or utilized in another embodiment has been describedabove, it should be appreciated that other elements of the variousembodiments may be incorporated or utilized with any of the otherembodiments disclosed herein.

What is claimed is:
 1. A lift device comprising: a chassis; a platformconfigured to support a user; a lift assembly coupling the platform tothe chassis; an actuator configured to at least one of (a) move theplatform relative to the chassis or (b) propel the chassis; a sensorassembly, comprising: a bar including a first end portion coupled to theplatform and a second end portion opposite the first end portion; ahousing defining an aperture sized to receive the second end portion ofthe bar; and a sensor configured to provide a signal in response to atleast one of (a) the second end portion of the bar contacting the sensoror (b) the second end portion of the bar exiting the aperture; and acontroller operatively coupled to the sensor and the actuator andconfigured to control the actuator based on the signal from the sensor.2. The lift device of claim 1, wherein the sensor is positioned tocontact the second end portion when the second end portion is receivedwithin the aperture.
 3. The lift device of claim 2, wherein the barincludes a resilient member extending between the first end portion andthe second end portion, and wherein the resilient member is configuredto resist the second end portion exiting the aperture.
 4. The liftdevice of claim 1, further comprising a hinge pivotally coupling thefirst end portion to the platform.
 5. The lift device of claim 4,wherein the hinge includes: a first hinge portion fixedly coupled to theplatform; and a second hinge portion pivotally coupled to the firsthinge portion and defining a bar aperture that receives the bartherethrough, wherein the bar is repositionable through the bar apertureto adjust a position of the second end portion of the bar.
 6. The liftdevice of claim 1, further comprising a plate coupling the first endportion of the to the platform, wherein the first end portion includes athreaded portion, wherein the sensor assembly further includes afastener in threaded engagement with the threaded portion and engaging afirst side of the plate.
 7. The lift device of claim 6, wherein thefastener is a first fastener, wherein the sensor assembly furtherincludes a second fastener in threaded engagement with the threadedportion and engaging a second side of the plate opposite the first sidesuch that the plate extends between the first fastener and the secondfastener.
 8. The lift device of claim 1, wherein the sensor isselectively repositionable relative to the platform to adjust a positionof the sensor relative to the second end portion of the bar.
 9. The liftdevice of claim 1, further comprising a user interface coupled to theplatform and operatively coupled to the controller, wherein thecontroller is configured to control the actuator based on an instructionreceived by the user interface, and wherein the bar extends above theuser interface.
 10. The lift device of claim 1, wherein the sensor isconfigured to provide the signal in response to the second end portionof the bar exiting the aperture.
 11. The lift device of claim 10,wherein the sensor includes a proximity sensor configured to indicatewhen the second end portion of the bar is within a threshold distance ofthe proximity sensor.
 12. The lift device of claim 11, wherein theproximity sensor is configured to distinguish between a metallic objectand a non-metallic object, and wherein the second end portion of the baris metallic.
 13. The lift device of claim 1, wherein the sensor isconfigured to provide the signal in response to the second end portionof the bar contacting the sensor.
 14. The lift device of claim 13,wherein the sensor includes an interface member configured to engage thesecond end portion of the bar and a biasing element configured to biasthe interface member toward the second end portion of the bar.
 15. Thelift device of claim 14, wherein the sensor includes a first switch anda second switch each coupled to the interface member and operativelycoupled to the controller; wherein the first switch is configured tochange from a first configuration to a second configuration in responseto the second end portion of the bar contacting the interface member;wherein the second switch is configured to change from a firstconfiguration to a second configuration in response to the second endportion of the bar contacting the interface member; and wherein, inresponse to an indication that at least one of (a) the first switch isin the first configuration of the first switch or (b) the second switchis in the first configuration of the second switch, the controller isconfigured to at least one of (a) stop movement of the actuator or (b)change a direction of the movement of the actuator.
 16. A sensorassembly for a lift device, comprising: a rod including a first endportion, a second end portion opposite the first end portion, and aresilient member extending between the first end portion and the secondend portion; a hinge coupled to the first end portion of the rod andconfigured to pivotally couple the rod to a platform of the lift device;a housing configured to be coupled to the platform, the housing definingan aperture sized to receive the second end portion of the rod; and asensor coupled to the housing and configured to provide a signal inresponse at least one of (a) the second end portion of the rodcontacting the sensor or (b) the second end portion of the rod exitingthe aperture, wherein the resilient member is configured to apply abiasing force to resist movement of the second end portion away from thesensor.
 17. The sensor assembly of claim 16, wherein the sensor includesa switch positioned to contact the second end portion of the rod whenthe second end portion is received within the aperture of the housing.18. The sensor assembly of claim 16, wherein the sensor includes aproximity sensor configured to detect a presence of the second endportion within the aperture without the proximity sensor contacting thesecond end portion.
 19. A lift device comprising: a chassis; a platformconfigured to support a user, the platform including a first rail and asecond rail; a user interface coupled to the platform and positionedbetween the first rail and the second rail; a lift assembly coupling theplatform to the chassis; an actuator configured to at least one of (a)move the platform relative to the chassis or (b) propel the chassis; asensor assembly, comprising: a rod including (a) a first end portioncoupled to the first rail, (b) a second end portion opposite the firstend portion, and (c) a resilient member extending between the first endportion and the second end portion; a plate coupled to the second railand defining an aperture sized to receive the second end portion of therod; a sensor positioned to detect the second end portion of the rodwhen the second end portion of the rod is received by the aperture; anda controller operatively coupled to the sensor and the actuator andconfigured to control the actuator in response to an indication from thesensor that the second end portion of the rod has exited the aperture.20. The lift device of claim 19, wherein the resilient member isconfigured to apply a biasing force to resist the second end portion ofthe rod exiting the aperture.